BATH — A few weeks after the start of 2019 comes another new year’s celebration – for the trees of the world.

Tu Bishvat, which literally means the 15th day of the Hebrew month of Shevat, is the “birthday of the trees,” a Jewish tradition dating back thousands of years. In honor of that holiday, Beth Israel Congregation and Kennebec Estuary Land Trust are holding a tree appreciation walk at Thorne Head Preserve.

The all-ages event begins at 1 p.m. Sunday, Jan. 20, and runs about 90 minutes. Participants can drive north in Bath on High Street, which dead-ends into the preserve’s parking lot. They are asked, should conditions be icy, to bring traction spikes or ice cleats.

Tu Bishvat, for environmentalists, is “an ancient and authentic Jewish ‘Earth Day’ that educates Jews about the Jewish tradition’s advocacy of responsible stewardship of God’s creation as manifested in ecological activism,” according to the article “Tu Bishvat 101” at myjewishlearning.com.

Beth Israel Rabbi Lisa Vinikoor said Jan. 11 the origins of Tu Bishvat “are around trying to figure out a yearly time to mark the tithing, or the taxes, on fruits in ancient Israel. … Eventually it led to a celebration of the products of trees.”

As this year’s holiday approached, Vinikoor contacted the land trust about conducting a joint program around the tradition.

“Our idea for this year was to partner with KELT, which is a wonderful community organization and (is composed of) experts on our local natural landscape, and do some kind of education and appreciation about the trees that are here,” Vinikoor said.

Her students questioned the timing of the celebration, given Maine’s frigid temperatures and spring being months away.

“I really wanted to emphasize for them, and for our community members, that actually things are going on with our trees, even though they look like nothing’s happening,” Vinikoor said.

Cheri Brunault, the land trust’s stewardship coordinator, said she was fascinated when Vinikoor reached out about the joint effort.

“One of the parts of KELT’s mission is actually to instill appreciation in the natural world, so this dovetails very nicely with what we want to do for the people of this area,” Brunault said.

During the walk she will guide next weekend, Brunault will delve into a variety of tree topics, such as how they grow, which species Maine has and their history here, along with the ways they benefit humans and wildlife alike.

Participants for the space-limited walk can register by calling the land trust at 442-8400 or logging onto www.kennebecestuary.org. A $5 donation is suggested, and registrants will be informed if inclement weather forces the walk to be rescheduled.

Echoing Vinikoor’s point, Brunault said trees aren’t exactly doing nothing right now. Although it’s still too early for them to bud, they are preparing for when it finally warms up.

“As soon as it warms up enough for water transport to happen in the tree, then you have this movement of sugars up to the leaves,” Brunault said, “so really the tree’s just waiting for those right conditions.”

She said there is enough photosynthetic activity for trees to perceive the length of the day.

“They’re watching,” Brunault explained. “… In a sense, the tree is observing its environment all winter long.”

Alex Lear can be reached at 780-9085 or alear@theforecaster.net. Follow him on Twitter: @learics.

Cheri Brunault, left, Kennebec Estuary Land Trust stewardship coordinator, discusses trees with Rabbi Lisa Vinikoor of Beth Israel Congregation in Bath. The land trust and synagogue are conducting a forest walk Jan. 20 that coincides with the Jewish holiday Tu Bishvat.